Failed to refresh the balancer settings :: caused by :: Could not find host matching read preference { mode: \"nearest\" } for set config"

Trying to add a shard. Looking at the logs in the config server the connection succeeds but afterwards balancer settings cannot be updated. The config server mentioned in the error message is a single node replica set. The shard replica set I’m trying to add is a single node replica set as well and is a bit slow to react due to network latencies.